American Express says it is uniquely positioned to offer the service thanks to its "closed-loop" business model in which it acts as card issuer, merchant acquirer and payment processing operator.

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In this context, a network effect is a positive feedback loop whereby platforms with stronger ecosystem of developers, content and service providers attract more customers.

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Oltio is a mobile payment service provider based in South Africa and will offer MasterCard?s open loop and remote payments solutions to merchants in the country.

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The Medilink bus service is to continue to operate between hospitals but is to miss out the Queen's Drive loop.

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When the Department of Homeland Security was created as part of the "war on terror, " the old Immigration and Naturalization Service (INS) was subsumed into the agency, and the repackaged bureaucracy was put back in the loop (the State Department is the access point for visas).

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